The present invention provides a process for the production of para ordered aromatic heterocyclic polymers, particularly polybisoxazoles and polybisthiazoles. While processes for the production of such polymers are known in the prior art, such prior art processes have yielded polymers which exhibit such disadvantages as undesirably low molecular weight.
It is known, for example, to produce such polymers by reacting a diaminodiol or a diaminodithiol with a dicarboxylic acid in the presence of polyphosphoric acid. For example, polyparaphenylenebenzobisoxazole can be produced by reacting 4,6-diaminoresorcinol with terephthalic acid in the presence of polyphosphoric acid. However, the polymer which is produced exhibits an undesirably low molecular weight, and, when spun, yields fibers having undesirably low strength properties, especially modulus.
In U.S. Pat. No. 3,313,783 is disclosed a process for the preparation of polybenzimidazoles which utilizes as a reactant at least one dicarboxylic acid or a derivative thereof. The dicarboxylic acid derivatives include the dichlorides. However, this patent neither discloses nor suggests the use of such a reactant in the production of polybisoxazoles and polybisthiazoles.
Therefore, it is an object of the present invention to provide a process for the production of high molecular weight para ordered aromatic heterocyclic polymer.
It is also an object of the present invention to provide a process for the production of high molecular weight para ordered heterocyclic polymer wherein the dichloride derivative of at least one aromatic dicarboxylic acid is utilized as a reactant.
It is also an object of the present invention to provide a process for the production of para ordered aromatic heterocyclic polymer which exhibits a number average molecular weight of at least approximately 10,000.
It is also an object of the present invention to provide a process for the production of high molecular weight para ordered aromatic heterocyclic polymer which is capable of being spun into fibers which exhibit high strength properties.
It is also an object of the present invention to provide a process for the production of fibrillar para ordered aromatic heterocyclic polymer.
These and other objects as well as the scope, nature, and utilization of the process of the present invention will be apparent from the following description and the appended claims.